LED lighting

Discussion in 'Electricians' Talk' started by AlexGoode, Apr 19, 2015.

  1. AlexGoode

    AlexGoode Member

    hello, I am mostly through an apprenticeship and have not done a great deal of work with led lights. i have the intention of fitting downlight fittings in my kitchen but when speaking to a worker in an electrical wholesaler, he had to put a type c breaker in for the start up current go 'halo' fittings- what are they compared to normal fittings?, but a work college put around 13 downlight fittings in his house on a type b breaker. can someone please explain. a general conversation is probably all i need to understand the principles.
     
  2. unphased

    unphased Screwfix Select

    Hello Alex. There are known issues with larger LEDs, such as floodlights at 50W and more, where several are used on one circuit. Type C will be useful for that. However, in a domestic environment, with 13 LED downlights there should be no problem. I have installed 20 plus JCC6 LEDs on a type B breaker without any issues. I would ignore the advice of the worker you met in the wholesalers as he will probably be telling you something he has overheard in conversation rather than having real knowledge. You will get a lot of that when you are out in the field.
     
  3. AlexGoode

    AlexGoode Member

    so what is a 'halo' fitting and what variety of fittings would i come acrsoss, e.g. when would i use mains and when would i use low voltage fittings
     
  4. AlexGoode

    AlexGoode Member

    am i ok to use the cable already going to one single fitting in a room and extending it?
     
  5. unphased

    unphased Screwfix Select

    LEDs have been heavily researched and the industry has produced a range of products. There are SELV products that require drivers and mains types with the drivers built in. LEDs are also being produced ain SMD form called surface mounted diodes which when mounted in a cluster produce intense light. These are used on floodlights where you can see a large yellow mass of SMDs bunched together.

    The biggest advantage of LEDs is the low energy they require. They have even produced lamps that are similar in shape as the old tungsten filament bulbs that can be used as direct replacements. The vast majority of LEDs being produced now are at mains voltage but there are still SELV versions available. I would say yes you can extend existing circuits to add these LEDs just the same as you would for the tungsten filament lamps.

    The car industry is embracing the new technology and using LEDs extensively instead of bulbs and lamps. Its a big industry now with lots of uses. Try researching it for more info. That's just a brief synopsis.
     
    FatHands likes this.
  6. AlexGoode

    AlexGoode Member

    So what is the difference between the mains and selv fittings for someone installing them and why would you actually choose one over the other. Also, I have installed 3 x 10 watt outside led fittings through a timer but the first one on the radial has blown- they were put in on xmas eve, is it just coincidence?
     
  7. unphased

    unphased Screwfix Select

    SELV is allowed as a protective measure so some situations may require the SELV over the mains. How long they last is a bit of a lottery. The manufacturers claim ridiculous time spans. JCC say 10 years on their JCC3, 6 and 10 mains, 5 years is commonly claimed. You should be able to take your failed unit back for exchange under warranty.
     
    FatHands likes this.
  8. AlexGoode

    AlexGoode Member

    thanks for the reply, it seems to be the sort of thing i should investigate and work out by working with led's. the thing that got me was two people saying completely different things so i wasn't sure who was right and who was wrong. after fitting 3x 10watt led fittings on a type b breaker, i just seem to have lost faith in led fittings at the minute, hopefully that will change.
     
  9. MGW

    MGW Screwfix Select

    As said a LED needs some form of current regulations with 230 volt units often it's a switch mode driver built into the lamp and you will see voltages like 150 ~ 250 volt only a switch mode driver could do that.

    With the 12 volt lamps some still have switch mode drivers but also some have a simple resistor. Resistors produce heat so waste energy. Also getting a 12 volt stabilised supply which matches the LED package is a problem. Some switch mode power supplies give out spikes which are not a problem for tungsten lamps but can blow an LED. Also there seems to be no AC or DC declared or voltage leeway so you have not idea what supply is required. Only safe way a 12VDC smoothed supply which can supply zero amps.

    So unless in a bathroom or some where else where 12 volt is a requirement best option is to used 230 volt types. Even then we have problems. Although we have rules for transmission lines where the feed and return should be a set distance apart so the capacitance and inductive element cancel each other out we tend to ignore it for 50 Hz only for extreme distances do we worry. The CB'er may talk about VSWR but for 50 Hz we treat it like DC. However with LED's using so little current running just the line to switches without the neutral can cause the lights to light dimly or flash. We sometimes fit suppressors to return the balance but unlike with radio where we have a VSWR meter to measure the reflected power with LED's it's trial and error. Often on make works A1 but another lights dim.

    Fitting a slightly larger bulb often removes the problem.
     
  10. AlexGoode

    AlexGoode Member

    thanks for replying, i have been looking into it, for example looking at how drivers softer the inrush but as a contractor, how would i look at installing led fittings, i spoke to someone at work and they say i can put over ten less in one rupees and won't have a problem with hem tripping out as they first get turned one, with normal switching using a line conductor and no neutral (contradicting what MGW says in his reply) is there an easier way to look at the whole situation?
     

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